Floor cleaning machine

ABSTRACT

A floor cleaning machine having a cleaning element arrangement with inner and outer cleaning elements that include inner and outer cleaning bodies, respectively, that extend jointly in the cleaning body plane and have first and second receiving openings, respectively. The inner and outer cleaning elements extend from the inner and outer cleaning bodies, respectively, away from the cleaning body plane to one side thereof. The inner cleaning body is arranged in the second receiving opening. The output shaft extends with an output shaft section into both the first and second receiving openings. First and second eccentric elements are attached to the output shaft section and to the inner and outer cleaning bodies, respectively, so that when the output shaft is rotated, the inner and outer cleaning bodies perform eccentric movements that are phase-shifted with respect to one another.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of German Patent Application No. 10 2021 116 683.7 filed Jun. 29, 2021, which is incorporated by reference as if set forth in detail herein.

FIELD

The present disclosure relates to a floor cleaning machine, in particular a scrubber dryer, having a cleaning element arrangement for engagement with a floor surface to be cleaned.

BACKGROUND

This section provides background information related to the present disclosure which is not necessarily prior art.

Such floor cleaning machines typically include a base and a cleaning element arrangement, which is arranged on an underside of the base, is held so as to be movable and is driven and has driven brushes which can engage with a floor surface to be cleaned. In this case, the brushes are used, in particular, for scrubbing a floor surface. Furthermore, the floor cleaning machine comprises a drive motor, preferably arranged on the base, for driving the cleaning element arrangement, and an operating bar, which is attached to the base, preferably movably, in particular pivotably via a joint, for guiding and actuating the floor cleaning machine. In this case, the machine can be guided and actuated directly by a user or can be fitted to a chassis and actuated from there.

EP 2 962 614 B1, for example, discloses a floor cleaning machine having a base and an operating bar which extends away therefrom and is connected to the base via a joint. Furthermore, two cleaning elements driven to rotate in opposite directions are provided on a base, the axes of rotation of said cleaning elements being inclined relative to one another with respect to a vertical. This ensures that, when the two cleaning elements rotate, a thrust is exerted on the base of the floor cleaning machine. However, because the cleaning elements are inclined relative to one another, the cleaning effect is not uniform in the region of the rotationally driven cleaning elements. On the contrary, the cleaning elements rest less strongly against the floor surface to be cleaned at the outer edge, with the result that the cleaning effect there is less. Moreover, the thrust produced continuously by the rotationally driven cleaning elements is frequently disadvantageous during operation. This is because a user must apply a considerable force to move the floor cleaning machine in other directions that deviate from the direction of thrust.

Furthermore, DE 44 25 782 C2 discloses a cleaning head for a floor cleaning machine, wherein eccentric elements are provided on a base and are arranged in a first plane. The eccentric elements are connected to cleaning elements, which are arranged in a second plane, which runs at a distance from the first plane. As a result, the cleaning head according to this prior art is associated with a comparatively high structural height and is thus unsuitable for a floor cleaning machine of the kind known, for example, from EP 2 962 614B 1, which is actuated manually by means of an operating bar.

Moreover, the prior art discloses floor cleaning machines which have a chassis, wherein the brush head thereof has two brushes which are arranged side-by-side and rotate in opposite directions. However, such floor cleaning machines are often large and difficult or impossible to manoeuvre in small spaces.

It is therefore one object of the present disclosure to provide a floor cleaning machine which is of particularly compact design and efficiently cleans the floor surface, while furthermore being easy to steer.

SUMMARY

This section provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features.

According to one aspect of the disclosure, this object can be achieved by a floor cleaning machine having a base and a cleaning element arrangement, held and driven on an underside of the base, for engagement with a floor surface, and a drive motor having an output shaft for driving the cleaning element arrangement, wherein the output shaft can be driven in rotation by the drive motor and extends along an output axis.

In some examples, an operating bar is attached to the base for the purpose of guiding and actuating the floor cleaning machine. Alternatively, however, it is also possible for an autonomously or manually controlled, driven chassis to be provided for movement over the floor surface to be cleaned, wherein the base is held on the chassis. According to the disclosure, the cleaning element arrangement has an inner cleaning element and an outer cleaning element arranged externally around the inner cleaning element, wherein the inner and outer cleaning elements are drivable in such a way that each of the cleaning elements performs an eccentric movement in which, when viewed perpendicularly to a cleaning body plane, each point of the cleaning element moves substantially circularly about an axis which runs parallel to the output axis, in which the axes for points which do not coincide, when viewed perpendicularly to the cleaning body plane, are different from one another, and in which, for one cleaning element, all points move in one direction of movement at any point in time, when viewed perpendicularly to the cleaning body plane, wherein the eccentric movements of the inner cleaning element and of the outer cleaning element are phase-shifted with respect to one another in such a way that, when viewed perpendicularly to the cleaning body plane, the direction of movement of the points of the inner cleaning element is different at any point in time from the direction of movement of the points of the outer cleaning element.

According to one aspect of the present disclosure, the inner cleaning element can have an inner cleaning body and the outer cleaning element has an outer cleaning body, wherein the inner and outer cleaning bodies extend jointly in the cleaning body plane, and wherein engagement elements extend from the inner and outer cleaning bodies away from the cleaning body plane to one side thereof. The inner cleaning body has a first receiving opening and the outer cleaning body has a second receiving opening, wherein the inner cleaning body is arranged in the second receiving opening.

The output shaft can extend with an output shaft section into the first and into the second receiving opening, wherein a first eccentric element is attached to the output shaft section and is connected to the inner cleaning body in such a way that, when the output shaft is rotated, the inner cleaning body performs the eccentric movement, wherein a second eccentric element is attached to the output shaft section and is connected to the outer cleaning body in such a way that, when the output shaft is rotated, the outer cleaning body performs the eccentric movement, and wherein the eccentric movements are phase-shifted with respect to one another.

Accordingly, the floor cleaning machine according to one example of the present disclosure can have a base to which an operating bar may be attached, which can then used to guide and actuate the floor cleaning machine. In this case, the operating bar is furthermore preferably attached pivotably to the base, thus enabling it to be pivoted in any desired directions relative to the base. In this case, the joint which connects the operating bar and the base to one another is preferably configured in such a way that, when the operating bar is rotated about its longitudinal axis, a torque is exerted on the base, which torque is oriented in such a way that, as a result, the base is rotated about a vertical axis which runs perpendicularly to the plane of the floor surface to be cleaned, on which the base with the cleaning element arrangement is arranged.

Alternatively, however, the floor cleaning machine can also have an autonomously or manually controlled, driven chassis for movement over the floor surface to be cleaned, wherein the base is held on the chassis. Thus, the disclosure is not restricted to hand-guided floor cleaning machines in which an operating bar for guiding the floor cleaning machine is provided on the base, but also includes floor cleaning machines with a chassis where the user sits or stands on the floor cleaning machine or walks behind or in front of the latter.

Furthermore, a drive motor and a cleaning element arrangement, which is driven by the latter and is provided to engage with a floor surface, are held on the underside of the base of the floor cleaning machine according to the disclosure. According to one aspect of the disclosure, the cleaning element arrangement has an inner cleaning element and an outer cleaning element arranged externally around the inner cleaning element, wherein the cleaning elements can be driven in such a way that they perform eccentric movements in the plane of the cleaning body which are phase-shifted with respect to one another. In the case of each of the cleaning elements, each point of the respective cleaning element, when viewed perpendicularly to the cleaning body plane, performs a circular movement about an axis during an eccentric movement, the axes being different from one another for points which, when viewed perpendicularly to the cleaning body plane, do not coincide. This means that the cleaning elements do not move as a whole about an axis, but each individual point of the respective cleaning element performs its own circular movement about its axis. Furthermore, the eccentric movement of the outer cleaning element is phase-shifted with respect to the eccentric movement of the inner cleaning element, with the result that, when viewed perpendicularly to the plane of the cleaning body, the points of the inner cleaning element move in a direction which deviates at any point in time from the direction in which the points of the outer cleaning element move. Thus, the cleaning elements do not perform any movements in the same direction.

Both cleaning elements, that is to say both the inner and the outer cleaning element, have cleaning bodies which are attached to the base in such a way that they both extend in the cleaning body plane. This means that at least parts of the inner cleaning body and at least parts of the outer cleaning body run in this common cleaning body plane, i.e. the cleaning body plane extends through these parts. From the cleaning bodies, cleaning elements, such as, for example, bristles but also pads, extend towards the floor surface to be cleaned and thus away from the cleaning body plane to one side thereof. In operation, the cleaning elements and thus the base with the cleaning elements rest with free ends remote from the cleaning bodies on the floor surface to be cleaned.

The inner cleaning body may have a first receiving opening and the outer cleaning body has a second receiving opening, wherein the receiving openings are configured in such a way that the inner cleaning body is arranged in the second receiving opening of the outer cleaning body.

In order to drive the cleaning bodies so that they perform the aforementioned eccentric movement, the output shaft of the drive motor may extend along the output axis into the first and the second receiving opening, with the result that one output shaft section is arranged inside the openings. The latter means that the output shaft section is arranged within the openings along a certain length between an upper end of one of the cleaning bodies, when viewed in the direction of the output axis, and a lower end of one of the cleaning bodies, once again when viewed along the output axis, and is surrounded by the cleaning bodies. A first and a second eccentric element are attached to this driven shaft section, wherein the first eccentric element is coupled to the first cleaning body and the second eccentric element is coupled to the second cleaning body in order to drive these eccentric elements to perform to the phase-shifted eccentric movements.

Accordingly, in the construction according to the disclosure of the cleaning element arrangement of the floor cleaning machine according to certain aspects of the present disclosure, the eccentric elements can be arranged in the plane in which the cleaning bodies also extend. They are therefore not offset with respect to the cleaning bodies when viewed in the axial direction of the output axis, but rather in the region in which the cleaning bodies also extend when viewed axially along the output axis. Therefore, the construction according to the disclosure of the drive of the cleaning bodies and thus of the cleaning elements is associated with a very low structural height. The drive motor can thus be arranged directly above the cleaning bodies of the cleaning element arrangement, and therefore the overall structural height of the base is comparatively low. Thus, a floor cleaning machine according to the disclosure can also be used in those areas in which there is comparatively little space in the vertical direction.

The first eccentric element may have a first eccentric disc, which is connected for conjoint rotation to the output shaft section and to the outer circumference of which a first receiving element is attached in such a way that it can be rotated with respect to the first eccentric disc about a first axis of rotation, which runs parallel to the output axis and is arranged at a distance from the latter, wherein the first receiving element is secured on the inner cleaning body, wherein the second eccentric element has a second eccentric disc, which is connected for conjoint rotation to the output shaft section, and to the outer circumference of which a second receiving element is attached in such a way that it can be rotated with respect to the second eccentric disc about a second axis of rotation, which runs parallel to the output axis and is arranged at a distance from the latter, wherein the second receiving element is secured on the outer cleaning body.

This construction ensures in a simple manner that the first and second cleaning body perform an eccentric movement. Specifically, when the output shaft and hence the output shaft section are driven in rotation, the outer circumference of the first and second eccentric discs performs an eccentric movement about the output axis. By virtue of the fact that the receiving elements are, in turn, arranged rotatably on the first and second eccentric discs and are connected for conjoint rotation to the cleaning body elements on the other side, the cleaning bodies as a whole perform an eccentric movement.

With such a construction, it is possible as a further preference for the first and the second eccentric disc to be arranged one behind the other on the output shaft section when viewed along the output axis, and for them to be connected thereto.

In a further example, the output shaft section may extend over the region of the output shaft in which the projection of the inner or outer brush body onto the output shaft falls. In particular, it is possible, when viewed in the axial direction of the output shaft, for the first eccentric element and the second eccentric element to be arranged in the region of the output shaft in which the projection of the inner or outer brush body onto the output shaft falls. In such an arrangement, the first and second eccentric discs, which are attached to the output shaft section, are then completely within the region in which the output shaft is surrounded by the cleaning bodies, and the first and second eccentric discs are thus not arranged outside this region, thus further minimizing the axial extent of the drive arrangement.

In order to further minimize the extent of the drive arrangement and, in particular, of the cleaning element arrangement in the axial direction of the output shaft, it is advantageous if the projection of the inner brush body onto the output shaft at least partially overlaps the projection of the outer brush body onto the output shaft. With such a construction, the outer cleaning body surrounds the inner cleaning body.

In a further example, the base can have a drive motor holding element, to which the drive motor is fixedly attached, wherein first elastic elements are provided, which are fixedly connected to the inner cleaning body and to the drive motor holding element, and wherein second elastic elements are provided, which are fixedly connected to the outer cleaning body and to the drive motor holding element. The elastic elements ensure that the cleaning elements can move out of a rest position to a certain extent, but rotation of the cleaning bodies is prevented. By virtue of the elastic elements, it is thereby ensured that the cleaning bodies can in fact carry out only an orbital movement but are prevented from rotating.

Optionally, the drive motor holding element can be held on the base in such a way as to be pivotable about a pivot axis running parallel to the brush plane. This ensures that the cleaning bodies and thus the cleaning elements can align themselves independently of the alignment of the base with respect to the floor surface to be cleaned, this alignment being to a certain extent independent of any forces which may be exerted on the base by an operating bar.

Furthermore, guide wheels, which can be rotatable about a common wheel axis, can be held on the base. Such guide wheels ensure that the direction of movement of the floor cleaning machine over a floor surface to be cleaned can be better predetermined by a user if an operating bar is provided on the base. If, as a further preference, the wheel axis and the pivot axis run parallel to one another, the wheels can be brought into engagement with the floor surface to be cleaned by a torque being exerted on the base via an optionally present operating bar, with the result that the base is pivoted with respect to the drive motor holding element. Thus, if a movement of the floor cleaning machine in a direction perpendicular to the wheel axis is desired, all that is required is to exert a corresponding force on the base with the aid of the operating bar. Operation is thereby made even easier.

Optionally, the eccentric movement of the inner cleaning element is phase-shifted by 180° with respect to the eccentric movement of the outer cleaning element, with the result that, when viewed perpendicularly to the cleaning body plane, the direction of movement of the points of the inner cleaning element is opposite to the direction of movement of the points of the outer cleaning element at any point in time. This can ensure that the forces which act on the base as a result of the eccentric movements of the cleaning elements and which result from the engagement of the engagement elements with the floor surface to be cleaned cancel each other out and there are no resultant restoring forces on the base, i.e. the latter is not moved in a specific direction. For this purpose, it is possible for the output axis, the first axis of rotation and the second axis of rotation to run in a common plane.

In order further to ensure that inertial forces generated during the respective eccentric movement as well as restoring forces due to the engagement of the cleaning elements with the floor surface to be cleaned cancel each other out, it is further preferred for the inner cleaning element and the outer cleaning element to be configured in such a way that their masses are equal, and/or for the inner cleaning element and the outer cleaning element to have engagement surfaces of the same size by means of which the cleaning elements engage with the floor surface.

Some exemplary embodiments of the present disclosure provide a floor cleaning machine where the outer cleaning element has a triangular outer contour in the brush plane. In such an example, it is possible for the sides of the triangular outer contour of the outer cleaning element to be of convex design. With such a construction, it is possible with the floor cleaning machine according to the disclosure to gain good access, in particular, even to corners and angled regions of the floor surface to be cleaned.

In situations where the second receiving opening has a triangular inner contour in the cleaning body plane, the inner cleaning element can have a triangular outer contour in the cleaning body plane. This ensures that when the cleaning elements are driven and the eccentric stroke is suitably selected, no area remains between the two which is not covered by cleaning elements of the cleaning elements, and therefore the outer and the inner cleaning elements engage together with as large a continuous surface as possible. As a particular preference, the sides of the triangular outer contour of the outer cleaning element are of convex design.

However, the present disclosure is not restricted to the cleaning elements having a triangular inner or outer contour. It is also possible, in plan view, for the cleaning elements to be designed as triangles with straight sides, as rectangles or as trapeziums, the orientation of an optionally present tip differing relative to the preferred direction of movement of the machine, i.e. the tip points in the direction of movement or in an opposite direction.

In a further embodiment, the inner cleaning element and the outer cleaning element have bristles pointing towards the floor surface as engagement elements, wherein the bristles of the inner cleaning element comprise a first group of bristles and wherein a subset of the first group of bristles is arranged uniformly inclined in a first direction with respect to the output axis, while the bristles of the first group which are not included in said subset extend parallel to the output axis, and/or wherein the bristles of the outer cleaning element comprise a second group of bristles and wherein a subset of the second group of bristles is arranged uniformly inclined in a first direction with respect to the output axis, while the bristles of the second group which are not included in said subset extend parallel to the output axis.

Since, in this embodiment, for one group of bristles on at least one of the cleaning elements, a subset of the bristles is inclined uniformly or in the same direction with respect to the output axis, the bristles of this subset offer a different resistance to a movement over the floor, depending on whether the movement takes place in the direction of the inclination or in the opposite direction thereto. This, in turn, leads to a thrust against the direction of the inclination. For the subset of the bristles of the group which is not inclined, the resistance is always the same, and therefore this subset does not contribute to or counteract the thrust generated by the group. By means of this thrust generated by the group, it is possible, for example in the case of a hand-guided floor cleaning machine, to assist a user in moving and steering the floor cleaning machine. The alignment of the inner and/or outer cleaning element can preferably be controlled in such a way that the inclined bristles and thus the thrust are directed in a desired direction.

The group of bristles in which one subset is inclined in a certain direction can include all the bristles provided on the cleaning element. However, it is also conceivable for a certain quantity of bristles not to be part of the group, such as, for example, those which are attached obliquely to the edge of the cleaning element.

Furthermore, in another embodiment, the floor cleaning machine according to the disclosure can have a cleaning liquid container, which is preferably attached to the base or the operating bar, wherein means are provided on the base which are connected to the cleaning liquid container and are configured to apply cleaning liquid to a floor surface on which the floor cleaning machine is arranged.

Optionally, the floor cleaning machine can be provided with a suction foot, attached to the base or to the operating bar, for sucking up cleaning liquid from the floor surface. Moreover, a suction device can be attached to the operating bar or to the base, which suction device acts on the suction foot with a suction air flow. Furthermore, a receiving container for cleaning liquid can be provided on the operating bar or the base, which container is connected to the suction device, thus enabling cleaning liquid to be conveyed from the suction foot into the receiving container by means of the suction air flow.

However, it is also possible for the floor cleaning machine with the construction according to the disclosure of the drive for the cleaning elements to be used together with a further floor cleaning machine, which is of self-propelled design, and for the latter to supply the drive motor and to feed in cleaning liquid, and for the suction device which is present thereon for sucking up cleaning liquid to be used to produce a suction air flow in the suction foot. Thus, it is not necessary for a battery unit, a suction turbine, a cleaning liquid container and a dirty water tank to be provided.

Further areas of applicability will become apparent from the description provided herein. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.

DRAWINGS

The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure.

FIG. 1 is a perspective view of a floor cleaning machine according to the present disclosure;

FIG. 2 is a cross-sectional view of the base of the floor cleaning machine from FIG. 1 ;

FIG. 3 is a perspective view from below of the cleaning element arrangement of the floor cleaning machine from FIG. 1 ; and

FIG. 4 is a cross-sectional view of the base of a floor cleaning machine of an alternative exemplary embodiment.

Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings.

DETAILED DESCRIPTION

FIG. 1 illustrates an exemplary embodiment of a floor cleaning machine 1 according to the present disclosure, which is designed here as a hand-guided scrubber dryer and which is provided with a cleaning element arrangement, by means of which cleaning liquid can be applied to the floor surface 3 (see FIG. 2 ) and which has cleaning elements for engagement with the floor surface 3 to be cleaned, and with a suction foot, by means of which scrubbing residues, including the cleaning liquid, can subsequently be sucked off. The floor cleaning machine 1 described here has an operating bar 7, which is attached to a base 5 of the floor cleaning machine 1 and will be described in detail below, wherein the operating bar 7 is pivotably attached to a base 5.

However, the present disclosure is not restricted to such hand-guided floor cleaning machines 1 with an operating bar 7 but can also be used in floor cleaning machines which have a chassis by means of which the floor cleaning machine can be moved over a floor surface to be cleaned, wherein a user either sits or stands on the floor cleaning machine or a user walks in front of or behind the machine. In this context, the floor cleaning machine can also be controlled autonomously, making it unnecessary for it to be guided by a user.

As already mentioned, the exemplary embodiment of a floor cleaning machine 1 according to the disclosure described here comprises a base 5, to which an operating bar 7 is pivotably attached via a joint 9. The operating bar 7 extends from the joint 9, via which it is pivotably connected to the base 5, along a longitudinal axis 11 to an actuating end 13. In this case, the joint 9 is configured in such a way that, when the operating bar 7 is pivoted about the longitudinal axis 11, a torque is exerted on the base 5, with the result that the latter is pivoted about a vertical axis 15 with respect to the floor surface 3, the vertical axis 15 running perpendicularly to the floor surface 3. On account of its construction, the joint 9 therefore makes it possible for a user who grips the operating bar 7 at its actuating end 13 to be able to steer the base 5.

A cleaning liquid container 17 and a dirty water tank 19 are releasably attached to the operating bar 7 and are connected, in a manner still to be described, to the base 5 and to a suction foot 21, which is held pivotably on the base 5, via lines 23, 25. In this case, the suction foot 21 can be pivoted between the position shown in the figures, in which it is situated opposite the floor surface 3 to be cleaned, and a raised position, in which it is spaced apart from the floor surface 3.

Finally, a cleaning element arrangement 27, which is configured to engage with the floor surface 3 to be cleaned, is provided on the underside of the base 5, which faces the floor surface 3 to be cleaned, wherein the cleaning element arrangement 27 is driven by a drive motor 31, which is arranged in a housing 29 on the base. The drive motor 31 can be, for example, an electric motor which is supplied by a battery unit, not illustrated in the figures, which is attached to the base 5 or the operating bar 7. However, it is also conceivable in principle for the drive motor 31 to be driven by compressed air. This may be the case when the floor cleaning machine 1 is used as an accessory on a self-propelled machine.

Also arranged in the housing 29 of the base 5 is a suction turbine 33, the suction side of which is connected via line 25 to the upper end of the dirty water tank 19. The dirty water tank 19, in turn, is connected to the suction foot 21 via line 23. The suction turbine 33 forms a suction device, with the aid of which a suction air flow from the suction foot 21 into the dirty water tank 19 is generated, thus enabling cleaning liquid to be sucked off from the floor surface 3 to be cleaned. As can also be seen from FIG. 2 , further lines 35 are provided in the base 5, via which cleaning liquid can be applied from the cleaning liquid container 17, through the base 5, into the region of the cleaning element arrangement 27 and, in the process, onto the floor surface 3 to be cleaned.

As can be seen, in particular, from FIG. 2 , the drive motor 31 has an output shaft 39, which extends along an output axis 37 and is driven in rotation by the drive motor 31. Mounted one behind the other on the output shaft 39 when viewed in the axial direction of the output axis 37, for conjoint rotation therewith, are a first eccentric disc 41 and a second eccentric disc 43. A first receiving element 45 is secured in a rotatable manner via a first bearing 47 on the outer circumference of the first eccentric disc 41, wherein the first receiving element 45 is connected in a fixed manner to the inner cleaning body 49 of an inner cleaning element 51. Here, the first receiving element 45 is rotatable with respect to the first eccentric disc 41 about a first axis of rotation D1, which runs parallel to the output axis 37. In this case, the inner cleaning body 49 of the inner cleaning element 51 has a first receiving opening, in which the first receiving element 45 is received. In addition, the inner cleaning body 49 extends in a cleaning body plane 53 which, during the operation of the floor cleaning machine 1, if the latter is arranged on a floor surface 3 to be cleaned, extends substantially parallel to the plane of the floor surface 3 to be cleaned.

In a similar way, a second receiving element 55 is attached in a rotatable manner via a second bearing 57 to the outer circumference of the second eccentric disc 43, wherein the second receiving element 55 is connected in a fixed manner to an outer cleaning body 59 of an outer cleaning element 61. Here, the second receiving element 55 is rotatable with respect to the second eccentric disc 43 about a second axis of rotation D2, which runs parallel to the output axis 37 and the first axis of rotation D1. In this case, the outer cleaning body 59 has a second receiving opening, in which, on the one hand, the second receiving element 55 and, on the other hand, the inner cleaning body 49 of the inner cleaning element 51 are received. Therefore, the outer cleaning body 59 surrounds the inner cleaning body 49, and the outer cleaning element 61 is arranged externally around the inner cleaning element 51. Moreover, the outer cleaning body 59, and thus the outer cleaning element 61, also extends in the cleaning body plane 53.

Both the inner cleaning body 49 and the outer cleaning body 59 are arranged in the cleaning body plane 53, i.e. at least parts both of the inner cleaning body 49 and of the outer cleaning body 59 intersect the cleaning body plane 53 when viewed in cross section. Furthermore, it can be seen both from FIG. 2 and from FIG. 3 that the inner cleaning element 51 and the outer cleaning element 61 have engagement elements 63, which are secured on the respective cleaning body 49, 59, and point towards the side of the cleaning body plane 53 which faces the floor surface 3 to be cleaned. The engagement elements 63 are provided for the purpose of engaging with the floor surface 3 to be cleaned. In the exemplary embodiment described here, the engagement elements 63 are designed as bristles. However, it is also conceivable for these to be formed by pads or the like.

In the exemplary embodiment described here, the first and the second eccentric disc 41, 43 are furthermore arranged in such a way that the first and the second axis of rotation D1, D2 and the output axis 37 always run in a common plane when the output shaft 39 is rotating. This is associated with the fact that the first and second eccentric discs 41, 43 are secured on the output shaft 39 in a manner offset by 180° with respect to one another.

As can also be seen from FIG. 2 , the output shaft 39 has an output shaft section 39′ which extends into the first and into the second receiving opening of the inner cleaning body 49 and of the outer cleaning body 59 and which furthermore also extends over the region of the output shaft 39 on which the projection of the inner or the outer cleaning body 49, 59 onto the output shaft 39 falls. In this region, the first eccentric element 41 and the second eccentric element 43 are also arranged one behind the other when viewed in the axial direction of the output shaft 39. Finally, the inner and outer cleaning bodies 49, 59 are constructed and secured on the output shaft 39 via the first and second eccentric discs 41, 43 and the first and second receiving elements 45, 55 in such a way that the projection of the inner cleaning body 49 onto the output shaft 39 at least partially overlaps the projection of the outer cleaning body 59 onto the output shaft 39, thus ensuring that the axial extent of the structure comprising the two cleaning bodies 49, 59 along the output axis 37 is as short as possible.

In the exemplary embodiment described here, the inner cleaning element 51 and the outer cleaning element 61 are furthermore configured in such a way that their masses are equal, and the inner cleaning element 51 and the outer cleaning element 61 have engagement surfaces which are formed by the engagement elements 63 connected to them and by means of which they engage with the floor surface 3 to be cleaned, these engagement surfaces of the two cleaning elements 51, 61 being equal in size.

In addition, it can be seen especially from FIG. 3 that the outer cleaning element 51 has a triangular outer contour when viewed in the cleaning body plane 53, wherein the sides of the triangular outer contour are of convex design. Furthermore, the second receiving opening has a triangular inner contour in the cleaning body plane 53, and the inner cleaning element 51 likewise has a triangular outer contour in the cleaning body plane 53.

FIG. 2 furthermore shows that a drive motor holding element 65, to which, in turn, the drive motor 31 is fixedly attached, is provided on the base 5. The drive motor holding element 65 is held via elastic elements 66 in such a way that it can be pivoted with respect to the base 5, wherein the drive motor holding element 65 can be pivoted relative to the base 5, in particular about a pivot axis 67 which runs parallel to the cleaning body plane 53. In addition, the pivot axis 67 runs substantially perpendicularly to a direction in which the floor cleaning machine 1 is moved forwards in normal operation. Because the drive motor holding element 65 is held pivotably on the base 5 and is fixedly connected to the drive motor 31 and thus to the cleaning element arrangement 27, the inner and outer cleaning inner and outer elements 51, 61 can pivot relative to the base 5 and the alignment of the inner and outer cleaning elements 51, 61 can automatically adapt to the profile of the floor surface 3 without it being necessary for the user to have to pivot the base 5 to achieve this.

As can furthermore be seen from FIG. 2 , first elastic elements 69 are provided, which are connected fixedly, on the one hand, to the inner cleaning body 49 and fixedly, on the other hand, to the drive motor holding element 65. In the same way, second elastic elements 71 are provided, which are connected fixedly, on the one hand, to the outer cleaning body 59 and fixedly, on the other hand, to the drive motor holding element 65. In this case, the first and second elastic elements 69, 71 are configured in such a way that, although they are fixedly connected to the drive motor holding element 65 and the respective cleaning body 49, 59, they allow a limited movement of the inner and outer cleaning bodies 49, 59 parallel to the cleaning body plane 53.

When the drive motor 31 is switched on and the output shaft 39 rotates, the inner cleaning body 49 and the outer cleaning body 59, and thus the inner cleaning element 51 and the outer cleaning element 61, are set in an eccentric movement about the output axis 37. Such an eccentric movement is distinguished by the fact that, when viewed perpendicularly to the cleaning body plane 53, each point of the cleaning element 51 and of the second cleaning element 61 moves substantially circularly about an axis which runs parallel to the output axis 37, but the axes for points which do not coincide, when viewed perpendicularly to the cleaning body plane 53, are different from one another. For each of the inner and outer cleaning elements 51, 61, the situation is such that, during such an eccentric movement, all points of the cleaning element 51, 61 move in a single direction of movement at any point in time, when viewed perpendicularly to the plane of the cleaning body 53.

Owing to the arrangement of the first and second axis of rotation D1, D2 in a common plane together with the output axis 37 or the offset of the first and second eccentric discs 41, 43 by 180°, the eccentric movements of the inner cleaning element 51 and of the outer cleaning element 61 are phase-shifted with respect to one another in such a way that, when viewed perpendicularly to the cleaning body plane 53, the direction of movement of the points of the inner cleaning element 51 is opposite to the direction of movement of the points of the outer cleaning element 61 at any point in time. The eccentric movements are thus 180° phase-shifted with respect to one another.

Since the inner and outer cleaning bodies 49, 59 are connected to the drive motor holding element 65 via the first and second elastic elements 69, 71, and therefore can only perform a movement to a small extent relative to the drive motor holding element 65, the movement of the inner and outer cleaning bodies 49, 59 is restricted to the above-described eccentric movement, and the inner and outer cleaning bodies 49, 59 cannot also rotate about their respective axes of rotation D1, D2 relative to the base 5.

In addition, the masses and the engagement surfaces of the inner and outer cleaning elements 51, 61 are equal in size, which, together with the always opposite movement of the inner and outer cleaning elements 51,61 results overall in the forces and torques generated as a result of the movement of the inner and outer cleaning elements 51, 61 cancelling each other out and no resultant forces acting on the base 5.

Finally, it can be seen from the figures that guide wheels 73, which are rotatable about a common wheel axis 75, are held on the base 5. This wheel axis 75 runs parallel to the pivot axis 67 and thus likewise parallel to the brush plane 53 and perpendicularly to the direction in which the floor cleaning machine 1 is moved over the floor surface 3 to be cleaned in normal operation. When the guide wheels 73 are resting on the floor surface 3 to be cleaned, the floor cleaning machine 1 can be moved comfortably along the direction defined by the wheel axis 75 without a user having to exert large forces on the operating bar 7. In this case, the guide wheels 73 can be attached to the base 5 at a height such that they rest on the floor surface 3 to be cleaned only if a corresponding force is exerted on the base 5 by means of the operating bar 7, as a result of which the base 5 is pivoted about the pivot axis 67 with respect to the drive motor holding element 65. In the case of such an arrangement of the guide wheels 73, the user determines whether the machine should execute a rectilinear movement or be moved without the guide wheels 73 coming into contact with the floor surface 3.

During operation of the floor cleaning machine 1 described above, cleaning liquid is applied to the floor surface 3 to be cleaned from the cleaning liquid container 17 via the line 35, while the drive motor 31 is simultaneously in operation, with the result that the inner and outer cleaning elements 51, 61 are driven to perform an eccentric movement, during which the engagement elements 63 engage with the floor surface 3 to be cleaned and clean the latter together with the applied cleaning liquid. Because of the eccentric movement of the two cleaning elements 51, 61, which is phase-shifted by 180°, no resultant forces, in particular about the vertical axis 15, are exerted on the base 5. As a result, a user can guide the floor cleaning machine 1 in a simple manner by means of the operating bar 7. Since the joint 9 is configured in the manner already described, the user can also easily change the orientation of the base 5 by rotating the operating bar 7 about its longitudinal axis 11. Since the inner and outer cleaning bodies 49, 59, and especially the outer cleaning body 61, are of triangular configuration, the floor cleaning machine 1 can also be moved effectively into angled regions. Moreover, during operation, cleaning liquid is sucked up again from the floor surface 3 to be cleaned via the suction foot 21 as a result of the suction air flow generated by the suction turbine 33, when the floor cleaning machine 1 is moved over the floor surface 3. This cleaning liquid laden with dirt is collected in the dirty water tank 19.

However, it is also possible, as is the case in the exemplary embodiment shown in FIG. 4 , for the inner cleaning element 51 and the outer cleaning element 61 to have bristles 77, 79 pointing towards the floor surface 3 as engagement elements, wherein the bristles 77 of the inner cleaning element 51 comprise a first group of bristles 77. At least a subset and, in the present exemplary embodiment, all, of the bristles 77 of the first group of bristles is/are arranged uniformly inclined in a first direction with respect to the output axis 37. In the same way, all the bristles 79 of the outer cleaning element are also arranged uniformly inclined in a first direction with respect to the output axis 37.

Since, in this embodiment, for at least one group and here even all the bristles 77, 79 on the inner and outer cleaning elements 51, 61 are inclined uniformly or in the same direction with respect to the output axis 37, the bristles 77, 79 offer a different resistance to a movement over the floor, depending on whether the movement takes place in the direction of the inclination or in the opposite direction thereto. This, in turn, leads to a thrust against the direction of the inclination. By means of the thrust produced in this way, it is possible, for example in the case of a hand-guided floor cleaning machine, to assist a user in moving and steering the floor cleaning machine.

The group of bristles in which at least a subset is inclined in a certain direction can include all the bristles provided on the cleaning element, as illustrated here. However, it is also conceivable for a certain quantity of bristles not to be part of the group, such as, for example, those which are attached obliquely to the edge of the cleaning element.

Since the arrangement comprising the drive motor 31 and the inner and outer cleaning elements 51, 61 has only a very short overall length when viewed in the axial direction of the output axis 37, the base 5 of the floor cleaning machine has only a very low height, and the floor cleaning machine 1 can also be moved into regions in which the space is severely limited in the vertical direction if the operating bar 7 is pivoted sharply relative to the vertical. In the case of the construction according to the disclosure, therefore, the drive of the inner and outer cleaning elements 51, 61 is associated with a very small overall size, and this greatly extends the possible uses of the floor cleaning machine 1 according to the disclosure. By virtue of the type of drive with which an eccentric movement of the inner and outer cleaning elements 51, 61 is generated, which are preferably phase-shifted by 180°, it is additionally ensured that a uniform cleaning effect is achieved over the entire area in which the inner and outer cleaning elements 51, 61 are in engagement with the floor surface 3 to be cleaned and, on the other hand, that no resultant torques are exerted on the base 5 of the floor cleaning machine 1.

In the exemplary embodiment described above, the floor cleaning machine 1 has, in addition to a battery unit, a suction turbine 33, a cleaning liquid container 17 and a dirty water tank 19. However, it is conceivable for the floor cleaning machine 1 with the above-described construction of the drive for the inner and outer cleaning elements 51, 61 to be used together with a further floor cleaning machine, which is of self-propelled design, and for the latter to supply the drive motor 31 and to feed in cleaning liquid, and for the suction device which is present thereon for sucking up cleaning liquid to be used to produce a suction air flow in the suction foot. Thus, it is not necessary for a battery unit, a suction turbine, a cleaning liquid container and a dirty water tank to be provided.

The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.

LIST OF REFERENCE SIGNS

-   1 floor cleaning machine -   3 floor surface -   5 base -   7 operating bar -   9 joint -   11 longitudinal axis -   13 actuating end -   15 vertical axis -   17 cleaning liquid container -   19 dirty water tank -   21 suction foot -   23 line -   25 line -   27 cleaning element arrangement -   29 housing -   31 drive motor -   33 suction turbine -   35 line -   37 output axis -   39 output shaft -   39′ output shaft section -   41 first eccentric disc -   43 second eccentric disc -   45 first receiving element -   47 first bearing -   49 inner cleaning body -   51 inner cleaning element -   53 cleaning body plane -   55 second receiving element -   57 second bearing -   59 outer cleaning body -   61 outer cleaning element -   63 engagement element -   65 drive motor holding element -   66 elastic element -   67 pivot axis -   69 first elastic elements -   71 second elastic elements -   73 guide wheel -   75 wheel axle -   77 bristles -   79 bristles 

1. A floor cleaning machine comprising: a base, and a cleaning element arrangement, held on an underside of the base, the cleaning element arrangement being configured for engagement with a floor surface, and a drive motor having an output shaft for driving the cleaning element arrangement, wherein the output shaft is drivable in rotation by the drive motor and extends along an output axis, wherein the cleaning element arrangement comprises an inner cleaning element and an outer cleaning element that is arranged externally around the inner cleaning element, wherein the inner and outer cleaning elements are drivable in such a way that each of the inner and outer cleaning elements performs an eccentric movement in which, when viewed perpendicularly to a cleaning body plane, each point of each of the inner and outer cleaning elements moves substantially circularly about an axis which runs parallel to the output axis, in which the axes for points which do not coincide, when viewed perpendicularly to the cleaning body plane, are different from one another, and in which, for one cleaning element, all points move in one direction of movement at any point in time, when viewed perpendicularly to the cleaning body plane, wherein the eccentric movements of the inner cleaning element and of the outer cleaning element are phase-shifted with respect to one another in such a way that, when viewed perpendicularly to the cleaning body plane, the direction of movement of the points of the inner cleaning element is different at any point in time from the direction of movement of the points of the outer cleaning element, wherein the inner cleaning element has an inner cleaning body and the outer cleaning element has an outer cleaning body, wherein the cleaning bodies extend jointly in the cleaning body plane, and wherein engagement elements extend from the cleaning bodies away from the cleaning body plane to one side thereof, wherein the inner cleaning body has a first receiving opening and the outer cleaning body has a second receiving opening, wherein the inner cleaning body is arranged in the second receiving opening, wherein the output shaft extends with an output shaft section into the first and second receiving openings, wherein a first eccentric element is attached to the output shaft section and is connected to the inner cleaning body in such a way that, when the output shaft is rotated, the inner cleaning body performs the eccentric movement, and wherein a second eccentric element is attached to the output shaft section and is connected to the outer cleaning body in such a way that, when the output shaft is rotated, the outer cleaning body performs the eccentric movement.
 2. The floor cleaning machine of claim 1, further comprising an autonomously or manually controlled driven chassis for movement over the floor surface to be cleaned, wherein the base is held on the chassis.
 3. The floor cleaning machine of claim 1, further having an operating bar, attached to the base, for guiding and actuating the floor cleaning machine.
 4. The floor cleaning machine of claim 3, wherein the operating bar extends along a longitudinal axis and is pivotably attached to the base via a joint in such a way that it can be pivoted in any direction relative to the base, wherein the joint is configured in such a way that a torque is exerted on the base when the operating bar is rotated about its longitudinal axis, said torque being oriented in such a way as to cause the base to rotate about a vertical axis which runs perpendicularly to the cleaning plane.
 5. The floor cleaning machine of claim 1, wherein the first eccentric element has a first eccentric disc, which is connected for conjoint rotation to the output shaft section and to an outer circumference of which a first receiving element is attached in such a way that it can be rotated with respect to the first eccentric disc about a first axis of rotation, which runs parallel to the output axis and is arranged at a distance from the latter, wherein the first receiving element is secured on the inner cleaning body, and wherein the second eccentric element has a second eccentric disc, which is connected for conjoint rotation to the output shaft section, and to the outer circumference of which a second receiving element is attached in such a way that it can be rotated with respect to the second eccentric disc about a second axis of rotation, which runs parallel to the output axis and is arranged at a distance from the latter, wherein the second receiving element is secured on the outer cleaning body.
 6. The floor cleaning machine of claim 5, wherein the first and the second eccentric discs are arranged one behind the other on the output shaft section when viewed along the output axis and are connected thereto.
 7. The floor cleaning machine of claim 1, wherein the output shaft section extends over a region of the output shaft in which a projection of the inner or outer cleaning body onto the output shaft falls.
 8. The floor cleaning machine of claim 1, wherein, when viewed in the axial direction of the output shaft, the first eccentric element and the second eccentric element are arranged in a region of the output shaft in which a projection of the inner or outer cleaning body onto the output shaft falls.
 9. The floor cleaning machine of claim 1, wherein a projection of the inner cleaning body onto the output shaft at least partially overlaps a projection of the outer cleaning body onto the output shaft.
 10. The floor cleaning machine of claim 1, wherein a drive motor holding element, to which the drive motor is fixedly attached, is provided on the base, wherein first elastic elements are provided, which are fixedly connected to the inner cleaning body and to the drive motor holding element, and wherein second elastic elements are provided, which are fixedly connected to the outer cleaning body and to the drive motor holding element.
 11. The floor cleaning machine of claim 10, wherein the drive motor holding element is held on the base in such a way as to be movable.
 12. The floor cleaning machine of claim 1, wherein guide wheels, which are rotatable about a common wheel axis, are held on the base.
 13. The floor cleaning machine of claim 24, wherein the wheel axis and the pivot axis run parallel to one another.
 14. The floor cleaning machine of claim 1, wherein the eccentric movement of the inner cleaning element is phase-shifted by 180° with respect to the eccentric movement of the outer cleaning element, with the result that, when viewed perpendicularly to the cleaning body plane, the direction of movement of the points of the inner cleaning element is opposite to the direction of movement of the points of the outer cleaning element at any point in time.
 15. The floor cleaning machine of claim 5, wherein the output axis, the first axis of rotation and the second axis of rotation run in a common plane.
 16. The floor cleaning machine of claim 1, wherein the inner cleaning element and the outer cleaning element are configured in such a way that their masses are equal, and/or wherein the inner cleaning element and the outer cleaning element have engagement surfaces of the same size by means of which the cleaning elements engage with the floor surface.
 17. The floor cleaning machine of claim 1, wherein the outer cleaning element has a triangular outer contour in the cleaning body plane.
 18. The floor cleaning machine of claim 0, wherein the sides of the triangular outer contour of the outer cleaning element are of convex design.
 19. The floor cleaning machine of claim 1, wherein the second receiving opening has a triangular inner contour in the cleaning body plane, and wherein the inner cleaning element has a triangular outer contour in the cleaning body plane.
 20. The floor cleaning machine of claim 1, wherein the inner cleaning element and the outer cleaning element have bristles pointing towards the floor surface as engagement elements, wherein the bristles of the inner cleaning element comprise a first group of bristles and wherein a subset of the first group of bristles is arranged uniformly inclined in a first direction with respect to the output axis, while the bristles of the first group which are not included in said subset extend parallel to the output axis, and/or wherein the bristles of the outer cleaning element comprise a second group of bristles and wherein a subset of the second group of bristles is arranged uniformly inclined in a first direction with respect to the output axis, while the bristles of the second group which are not included in said subset extend parallel to the output axis.
 21. The floor cleaning machine of claim 1, having a cleaning liquid container coupled to the base, wherein a cleaning fluid dispensing system is provided on the base and which is connected to the cleaning liquid container, the cleaning fluid dispensing system being configured to apply cleaning liquid from the cleaning liquid container to a floor surface on which the floor cleaning machine is arranged.
 22. The floor cleaning machine of claim 1, having a suction foot coupled to the base that is configured for sucking up cleaning liquid from the floor surface.
 23. The floor cleaning machine of claim 22, wherein a suction device is coupled to the base, which suction device acts on the suction foot with a suction air flow.
 24. The floor cleaning machine of claim 11, wherein the drive motor holding element is pivotable relative to the base about a pivot axis that runs parallel to the cleaning body plane.
 25. The floor cleaning machine of claim 22, further having an operating bar, attached to the base, for guiding and actuating the floor cleaning machine, and wherein the suction foot is attached to the operating bar.
 26. The floor cleaning machine of claim 23, further having an operating bar, attached to the base, for guiding and actuating the floor cleaning machine, and wherein the suction foot is attached to the operating bar. 